1. Field of Technology
The embodiments herein relate to a display panel for a display device, and particularly, a touch integrated display panel of which a touch electrode is positioned inside of a display panel of a display device.
2. Description of the Prior Art
Requirements for a display device displaying an image have been increasing in various forms according to development of information society. In recent times, various display devices such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, an organic light emitting diode display device (OLED) have been utilized.
Among these display devices, the LCD device includes an array substrate including a thin film transistor, an upper substrate including a color filter and/or a black matrix etc., and a liquid crystal layer formed between the array substrate and the upper substrate, and the LCD device is a device displaying an image by controlling an alignment state of the liquid crystal layer according to an electric field applied between both electrodes of a pixel area and controlling transmittance of light according to the alignment state of the liquid crystal in the liquid crystal layer.
A display panel of the LCD device is defined as an active area (an active area, AA) providing the image to a user and a non-active area (a non-active area, NA) which is a peripheral area of the active area, and the display panel is usually fabricated by combining a first substrate which is the array substrate in which a pixel area is defined due to forming of the thin film transistor etc. and a second substrate which is the upper substrate in which the black matrix and/or the color filter layer etc. are formed.
The array substrate or the first substrate in which the thin film transistor is formed includes a plurality of gate lines GL extending in a first direction and a plurality of data lines DL extending in a second direction perpendicular to the first direction, and a pixel area P is defined by each of the gate lines and the data lines. In the pixel area P, at least one of the thin film transistors is formed, and a gate electrode and the source electrode of each of the thin film transistors may be respectively connected to the gate line and the data line.
In addition, a gate driving unit (a gate driving circuit) and a data driving unit (a data driving circuit) are formed in the non-active area or outside of the display panel so as to respectively provide a gate signal and a data signal to each of the gate lines and the data lines for driving each of the pixels.
The gate driving circuit may be simultaneously formed on the non-active area of the active area in a process of forming various signal lines and the pixel of the display panel, and thus as a result, the gate driving circuit may be formed in a gate-in-panel (GIP) type of which the gate driving circuit is included inside of the display panel.
In addition, a recent display panel usually has a touch function sensing a touch input such as a stylus pen or a user finger, and a type of which a touch screen is fabricated separately from the display panel to be disposed on the display panel, a touch integrated display panel of which a touch electrode and so on required to recognize a touch are included in the display panel when the display panel is fabricated, and so on have been developed.
The touch integrated display panel is called an “in-cell touch”, and in the touch integrated display panel, usually a common electrode (Vcom) providing a common voltage to a pixel of the display panel is processed in a specific type to be used as the touch electrode.
Meanwhile, the touch electrode is formed by dividing the common electrode in a size of a touch unit sensor having a uniform size, and the touch unit sensors are connected to a touch circuit unit through a touch electrode connection line.
The touch circuit unit measures a touch input signal, for example a capacitance change and so on, generated from some of the touch unit sensors to sense a touch position on the display panel.
At this time, the touch unit sensor is a unit of a touch electrode having a specific area for the touch recognition, the touch unit sensor is formed as a size of including several tens to several hundreds of the pixels, and a number of the touch unit sensors formed in horizontal and vertical directions in the whole active area may be usually defined as a touch channel number.
Meanwhile, a touch is usually measured by sensing a change of a capacitance, and the capacitance is a function with respect to an area of an electrode, therefore it is preferable that the sizes of the touch unit sensors are uniform in the whole display panel.
However, the sizes of the touch unit sensors may not be the same in the whole active area according to a resolution of the display panel, that is a pixel number in the horizontal and vertical directions, and an arrangement of the touch unit sensors and so on, and thus sensitivity of the touch recognition and touch accuracy may decrease.